Several studies have assessed the presence of microplastics (MPs) in human biological fluids and tissues highlighting potential health risks associated to oxidative stress, inflammation, immune dysfunction, neurotoxicity and reprotoxicity. However, only few studies have evaluated MP presence and effects in ovarian tissues of mammalians and, to date, no studies have detected MPs in human ovarian follicular fluids. Based on these premises, in this study, 18 women (undergoing assisted reproductive treatment at In Vitro Fertilisation center in Salerno, Southern Italy) were selected to assess the presence of MPs in follicular fluid. Plastic particles < 10 µm were measured using Scanning Electron Microscopy (SEM) coupled with an EDX (X Energy Dispersion) detector. MPs (size <10 µm) were detected in 14 out of 18 samples of follicular fluid, with an average concentration of 2191 particles/mL (0-7181particles/mL) and with a mean diameter of 4.48 µm (3.18-5.54 µm). Moreover, a significant correlation between MP concentration in follicular fluid samples and Follicle-Stimulating Hormone (FSH) (p-value <0.05), as well as a weak (non-significant) correlation with Body Mass Index (BMI), age and 17β-estradiol (E2), was found. On the contrary, no correlation with anti-Müllerian Hormone (AMH), fertilization outcomes, miscarriages, or live birth was observed. Since several studies on animal models have demonstrated the negative effects of MPs on ovarian function, the present study, that verified for the first time the presence of MPs in human follicular fluid, is of great significance for the scientific community in terms of raising awareness of the impact that these increasingly pervasive emerging contaminants have on reproductive function and human health.

The widespread occurrence of microplastics (MPs) and endocrine-disrupting compounds as bisphenol A (BPA) poses risks to aquatic life. This study evaluates the effects of polystyrene (PS) MPs and BPA, individually and conjugated, on embryonic development of black sea urchin Arbacia lixula, an ecologically relevant bioindicator. Embryos were exposed to 1 and 5 µm PS MPs (10 µg/mL), BPA (5 and 25 µM), and BPA-sorbed PS MPs. A multi-endpoint approach was employed, integrating embryotoxicity assays, morphological evaluation, metabolomics, and enzymatic biomarkers of oxidative stress and neurotoxicity. Size-dependent accumulation of PS MPs was observed. BPA caused pronounced skeletal abnormalities and developmental arrest, whereas when adsorbed onto MPs exhibited mitigated toxicity, even with a higher internalization of particles. Metabolomics revealed significant alterations in neuromodulatory, energetic, and osmoregulatory pathways in all treatments. Similarly, enzymatic assays indicated redox imbalance and inhibited acetylcholinesterase activity. While both PS MPs and BPA, alone and conjugated, induced impaired embryogenesis, no synergistic effect between the toxicants was observed, likely due to the low sorption capacity of BPA on PS MPs. The absence of a synergistic effect between PS MPs and BPA suggests that, under the tested acute exposure conditions, microplastics may modulate rather than exacerbate BPA toxicity. Nonetheless, their co-occurrence can influence exposure routes and developmental processes, with relevant ecological implications for marine invertebrate early life stages. Therefore, even weak and transient particle-pollutant interactions can modulate contaminant behaviour and toxicity, reinforcing the need to incorporate adsorption/desorption dynamics rather than mixture scenarios into environmental hazard assessments of emerging pollutants.

Background: The six Platinum group metal elements (PGEs) comprising Ruthenium, Rhodium, Palladium, Platinum, Iridium and Osmium are grouped together in the periodic table. Human activities are mostly responsible for releasing PGEs into the environment. This systematic review focused on three PGEs with the greatest anthropogenic use, including in vehicle catalytic converters: Platinum (Pt), Palladium (Pd), and Rhodium (Rh). Consequently, these represent the greatest contributors to environmental pollution. The current review of in vivo toxicological studies (mammalian models) and in vitro cell exposure studies examined the potential harmful effects of these metalloids to mammalians, and their possible toxicity to human health. Methods: We applied Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to conduct a comprehensive search and evaluation of records in the available literature published between 01/01/2009 and 01/15/2024 in four databases. PROSPERO code ID: CRD42024471558. Results concerning the health effects of PGEs were extracted from articles according to the inclusion and exclusion criteria. After screening the records for eligibility, 22 studies were included in the final analysis. Results: This systematic review revealed that airborne PGEs significantly increased the activation of pathologic pathways in several human organs and/or perturbed various metabolic pathways. In view of the known pro-inflammatory and organ-degenerative effects of PGEs, the paucity of studies on the effect of PGEs on the central nervous system and on possible correlations with neurodegenerative diseases were particularly evident. Conclusions: The clinical complexity and chronic nature of PGE-related pathologies indicate that targeted research is essential. In light of the increasing incidence of non-communicable diseases, particular attention should be paid to the design of epidemiological studies and to environmental monitoring services.